:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-elevated: #fafafa;
  --text: #111111;
  --muted: #6b6b6b;
  --link: #0066cc;
  --border: #ececec;
  --accent: #ff7a00;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0a0a;
    --bg-elevated: #141414;
    --text: #e8e8e8;
    --muted: #888888;
    --link: #6cc8ff;
    --border: #222222;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
        "PingFang TC", "Heiti TC", Helvetica, Arial, sans-serif;
  margin: 0;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: var(--link); }
code {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.92em;
  background: rgba(127,127,127,0.12);
  padding: 1px 5px;
  border-radius: 3px;
}
hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
.legal-container { max-width: 720px; margin: 0 auto; padding: 0 24px; }

/* ---------- Nav ---------- */
.nav {
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
  font-size: 14px;
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
}
.nav-inner { display: flex; align-items: center; gap: 20px; }
.nav-brand {
  font-weight: 600;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  display: block;
}
.nav-links {
  margin-left: auto;
  display: flex;
  gap: 20px;
  align-items: center;
  flex-wrap: wrap;
}
.nav-links a {
  color: var(--text);
  text-decoration: none;
  opacity: 0.75;
  transition: opacity 0.15s;
}
.nav-links a:hover { opacity: 1; }
.nav-lang {
  padding-left: 16px;
  border-left: 1px solid var(--border);
  color: var(--muted);
  font-size: 13px;
}
.nav-lang a { color: var(--muted); opacity: 1; }

/* ---------- Hero ---------- */
.hero {
  padding: 96px 24px 72px;
  text-align: center;
  max-width: 880px;
  margin: 0 auto;
}
.hero-icon {
  width: 128px;
  height: 128px;
  border-radius: 28px;
  margin: 0 auto 32px;
  display: block;
  box-shadow:
    0 1px 2px rgba(0,0,0,0.08),
    0 12px 32px rgba(0,0,0,0.18);
}
@media (prefers-color-scheme: dark) {
  .hero-icon {
    box-shadow:
      0 1px 2px rgba(0,0,0,0.4),
      0 16px 40px rgba(0,0,0,0.5);
  }
}
.hero h1 {
  font-size: 60px;
  line-height: 1.05;
  letter-spacing: -0.025em;
  margin: 0 0 20px;
  font-weight: 700;
}
.hero h1 .accent { color: var(--accent); }
.hero .tagline {
  font-size: 22px;
  color: var(--muted);
  max-width: 640px;
  margin: 0 auto 36px;
  line-height: 1.5;
}
.hero .ctas {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.hero .meta-line { color: var(--muted); font-size: 14px; margin-top: 12px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 14px 28px;
  background: var(--text);
  color: var(--bg);
  border-radius: 12px;
  text-decoration: none;
  font-weight: 600;
  font-size: 16px;
  border: none;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.15s;
}
.btn:hover { opacity: 0.85; }
.btn:active { transform: scale(0.98); }
.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--bg-elevated); opacity: 1; }

/* ---------- Sections ---------- */
.section {
  padding: 80px 0;
  border-top: 1px solid var(--border);
}
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}
.section h2 {
  font-size: 40px;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  font-weight: 700;
  line-height: 1.15;
}
.section .subtitle {
  color: var(--muted);
  font-size: 18px;
  margin: 0;
  line-height: 1.5;
}

/* ---------- Features grid ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}
.feature {
  padding: 8px 0;
}
.feature h3 {
  font-size: 18px;
  margin: 0 0 8px;
  font-weight: 600;
  letter-spacing: -0.005em;
}
.feature p {
  color: var(--muted);
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
}

/* ---------- Pricing ---------- */
.pricing {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 980px;
  margin: 0 auto;
}
.tier {
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 36px 28px;
  background: var(--bg-elevated);
  display: flex;
  flex-direction: column;
}
.tier-pro {
  border-color: var(--accent);
  border-width: 2px;
  position: relative;
}
.tier-pro::before {
  content: attr(data-badge);
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: white;
  font-size: 11px;
  padding: 5px 14px;
  border-radius: 20px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.tier h3 { margin: 0 0 8px; font-size: 22px; font-weight: 600; }
.tier .price {
  font-size: 38px;
  font-weight: 700;
  margin: 0 0 4px;
  letter-spacing: -0.025em;
  line-height: 1.1;
}
.tier .price small { font-size: 15px; font-weight: 500; color: var(--muted); }
.tier .price-note {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 24px;
  min-height: 1.5em;
}
.tier ul { list-style: none; padding: 0; margin: 0 0 8px; flex: 1; }
.tier li {
  padding: 10px 0;
  font-size: 14.5px;
  border-bottom: 1px solid var(--border);
  line-height: 1.45;
}
.tier li:last-child { border-bottom: none; }
.tier li::before {
  content: "✓";
  color: var(--accent);
  margin-right: 8px;
  font-weight: 700;
}

/* ---------- FAQ ---------- */
.faq { max-width: 760px; margin: 0 auto; }
.faq details {
  border-top: 1px solid var(--border);
  padding: 18px 0;
}
.faq details:last-of-type { border-bottom: 1px solid var(--border); }
.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 4px 0;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: "+";
  color: var(--muted);
  font-weight: 400;
  font-size: 20px;
  width: 16px;
  display: inline-block;
  transition: transform 0.15s;
}
.faq details[open] summary::before { content: "−"; }
.faq details p {
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.7;
  padding-left: 26px;
}
.faq details p + p { margin-top: 10px; }

/* ---------- Privacy callout ---------- */
.callout {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  max-width: 760px;
  margin: 0 auto;
}
.callout p { margin: 0; line-height: 1.7; font-size: 16px; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  font-size: 13px;
  color: var(--muted);
  margin-top: 40px;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-links a { color: var(--muted); text-decoration: none; opacity: 0.85; }
.footer-links a:hover { color: var(--text); opacity: 1; }

/* ---------- Legal pages ---------- */
.legal-content { padding: 48px 0 80px; }
.legal-content h1 {
  font-size: 32px;
  margin: 0 0 6px;
  letter-spacing: -0.01em;
  font-weight: 700;
}
.legal-content h2 {
  font-size: 19px;
  margin: 36px 0 8px;
  letter-spacing: -0.005em;
  font-weight: 600;
}
.legal-content .meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 32px;
}
.legal-content p, .legal-content ul { margin: 8px 0; }
.legal-content ul { padding-left: 22px; }
.legal-content li { margin: 4px 0; }

/* ---------- Support page ---------- */
.support-intro {
  max-width: 720px;
  margin: 0 auto 48px;
  text-align: center;
}
.support-intro h1 {
  font-size: 44px;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
  font-weight: 700;
}
.support-intro p { color: var(--muted); font-size: 18px; margin: 0; }
.contact-card {
  max-width: 720px;
  margin: 0 auto 56px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
}
.contact-card h2 {
  font-size: 18px;
  margin: 0 0 12px;
  font-weight: 600;
}
.contact-card p { margin: 8px 0; line-height: 1.6; font-size: 15px; }
.contact-card a { font-weight: 600; }

/* ---------- Mobile ---------- */
@media (max-width: 640px) {
  .nav { padding: 12px 0; }
  .nav-inner { gap: 12px; }
  .nav-links { gap: 14px; font-size: 13px; }
  .nav-lang { padding-left: 10px; }
  .hero { padding: 56px 20px 48px; }
  .hero-icon { width: 96px; height: 96px; border-radius: 22px; margin-bottom: 24px; }
  .hero h1 { font-size: 40px; letter-spacing: -0.02em; }
  .hero .tagline { font-size: 17px; }
  .section { padding: 56px 0; }
  .section-header { margin-bottom: 40px; }
  .section h2 { font-size: 30px; }
  .section .subtitle { font-size: 16px; }
  .tier { padding: 28px 22px; }
  .legal-content h1 { font-size: 26px; }
  .support-intro h1 { font-size: 34px; }
}